The first practical all-optical device that can remove both phase and amplitude noise from an optical data signal during the signal regeneration process is reported this week in Nature Photonics. The research will advance the performance of next-generation telecommunications systems.

Most optical networks encode data through the on?off switching of light. To cope with growing bandwidth demands, advanced modulation formats that can also encode data in the phase and amplitude of light are now being investigated. However, the performance of these systems is severely compromised by phase noise.

The phase-sensitive amplification scheme of David Richardson and colleagues suppresses the phase and amplitude noise during signal regeneration. The scheme takes an incoming noisy data signal and restores its fidelity, therefore acting as a true 'black box' signal regenerator.